The present disclosure relates to methods for forming transistors and transistor devices, and more specifically, to transistor devices that utilize selective undercut at the corner where the gate conductor contacts the gate insulator to control performance characteristics.
Integrated circuit transistors perform many useful functions within modern electronic devices. Such devices come in many shapes, types, and sizes; and diverse manufacturing processes have been developed in order to make transistors more efficient, more reliable, less expensive, and smaller.
For example, the switching performance of radio frequency (RF) field effect transistor (FET) devices can be optimized by reducing overlap capacitance and increasing breakdown voltage. Technical solutions that improve these parameters, such as thicker gate oxide or reduced extension implant dose, are detrimental to other switch device metrics, such as high linear drive current (low on-resistance). These parameters define one design trade-off space for field effect transistors used in radio frequency switching applications.